Hi
1) 6 months
2) 1 year
They didn't ask me about travel insurance at the airport anyway. I did have a returning flight for 6 months later as I was returning home for Christmas and to be fair you don't know if you're going to enjoy your time in Canada and want to leave early. When I got to Vancouver and had a job I joined the provincial coverage and have private medical through work anyway. I really don't think you need to purchase it for the entire timeframe.